Toyota Gain After Japan's Pain

The worst-performing stock market on the planet this year isn't an emerging market. It's Japan. And that's throwing up an interesting buying opportunity for Toyota Motor, the world's largest car maker.

The Nikkei 225 stock index fell 4.2% on Tuesday, and is now down 14% this year in local currency terms, underperforming the likes of Brazil, Russia and Turkey. Japan's market is heavy with export-reliant companies, a leveraged play on the world economy and a weak yen. Investors sense both drivers are under threat, with...